package com.wj.wjpicturebackend.manager.upload;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.http.HttpResponse;
import cn.hutool.http.HttpStatus;
import cn.hutool.http.HttpUtil;
import cn.hutool.http.Method;
import com.wj.wjpicture.infrastructure.exception.BusinessException;
import com.wj.wjpicture.infrastructure.exception.ErrorCode;
import com.wj.wjpicture.infrastructure.exception.ThrowUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;
import java.util.List;
@Service
@Slf4j
public class UrlPictureUpload extends PictureUploadTemplate {
    @Override
    protected void validPicture(Object inputSource) {
        String fileUrl = (String) inputSource;
        ThrowUtils.throwIf(fileUrl == null, ErrorCode.PARAMS_ERROR,"文件地址不能为空");
        try {
            // 1.验证URL格式
            new URL(fileUrl);
        } catch (MalformedURLException e) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"文件地址格式不正确");
        }

        // 2.校验URL协议
        ThrowUtils.throwIf(!(fileUrl.startsWith("http://") || fileUrl.startsWith("https://")),
                ErrorCode.PARAMS_ERROR,"仅支持HTTP或HTTPS协议的文件地址");

        // 3.发送HEAD请求以校验文件是否存在
        HttpResponse response = null;
        try {
            /*
            向fileurl发送HEAD请求后得到response，就可以从response里面获得文件类型(Content-Type)和文件大小(Content-Length)
             */
            response = HttpUtil.createRequest(Method.HEAD,fileUrl).execute();
            // 未正常返回，无需执行其他判断
            if(response.getStatus() != HttpStatus.HTTP_OK){
                return;
            }
            // 4.校验文件类型
            String contentType = response.header("Content-Type");
            if(StrUtil.isNotBlank(contentType)){
                // 允许的图片类型
                final List<String> ALLOW_CONTENT_TYPES = Arrays.asList("image/jpeg","image/jpg","image/png","image/webp");
                ThrowUtils.throwIf(!ALLOW_CONTENT_TYPES.contains(contentType.toLowerCase()),
                        ErrorCode.PARAMS_ERROR,"文件类型错误");
            }
            // 5.校验文件大小
            String contentLengthStr = response.header("Content-Length");
            if(StrUtil.isNotBlank(contentLengthStr)){
                try {
                    long contentLength = Long.parseLong(contentLengthStr);
                    final long TOW_MB = 2 * 1024 * 1024L;
                    ThrowUtils.throwIf(contentLength > TOW_MB,ErrorCode.PARAMS_ERROR,"文件大小不能超过2M");
                }catch (NumberFormatException e){
                    throw new BusinessException(ErrorCode.PARAMS_ERROR,"文件大小格式错误");
                }
            }
        }finally {
            if(response != null){
                response.close();
            }
        }
    }

    @Override
    protected String getOriginFilename(Object inputSource) {
        String fileUrl = (String) inputSource;
        return FileUtil.mainName(fileUrl);
    }

    @Override
    protected void processFile(Object inputSource, File file) throws Exception {
        String fileUrl = (String) inputSource;
        // 下载文件到临时目录
        HttpUtil.downloadFile(fileUrl,file);
    }
}
